JPS60307A - Measuring system of angle of inclination - Google Patents

Abstract

PURPOSE:To improve measuring accuracy by arranging a light reflecting means reflecting incident light in the same direction and forming a mask on a prescribed area on the mirror surface, displacing a light scanning surface so as to make the scanning surface coincide with a previously fixed reference line and detecting the quantity of displacement. CONSTITUTION:A coner cube CC is adjusted so that one side of the mask MA coincides with the previously fixed reference line X-X. A moving body V detects reflected light from the coner cube CC and counts up the number of pulses to discriminate whether the scanning line is ascended or descended from the reference line X-X. The scanning surface of an optical beam is rotated on the basis of the discriminated result so that the scanning line coincides with the reference line X-X. The rotation angle of the scanning surface of the optical beam is detected and the angle of inclination of the moving body V from the reference line X-X is measured.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inclination angle measurement system, and more particularly to an inclination angle measurement system that measures, for example, an angle made by a moving body with respect to a predetermined reference line.
related to measuring systems.

DESCRIPTION OF THE PRIOR ART Conventionally, various tilt angle detection devices have been proposed or realized for civil engineering machines, agricultural machines, and the like.

However, conventional tilt angle detection sensors often have low accuracy, and those with high accuracy have the disadvantage that they are expensive and require a mechanical device.

OBJECTS OF THE INVENTION Therefore, the main object of the present invention is to provide a completely new tilt angle measurement system that can perform highly accurate measurements with a simple configuration.

Structure of the Invention In summary, the present invention provides a light reflecting means that reflects incident light in the same direction and has a mask formed in a predetermined area of the light reflecting mirror surface, so that a sharply directional light beam is emitted from an object. The object side receives the light reflected from the light reflecting means, and based on the received light output, the light scanning surface formed by the light beam is displaced so that it coincides with a predetermined reference line. The angle formed by the object with respect to the reference line is detected by detecting the amount by which the optical scanning surface is displaced by the displacement means.

The above objects and other objects and features of the present invention will become more apparent from the following detailed description with reference to the drawings.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 is an external perspective view showing a corner cube as an example of light reflecting means used in the present invention. Inside this corner cube CC, a three-dimensional combination of three mirrors 1, 2, and 3 is housed, as shown in FIG. 2, for example. These mirrors 1 to 3 have respective reflecting mirror surfaces 1a and 2.
a and 3a are combined so that they are orthogonal to each other.

With such a configuration, the corner cube CC has optical properties as described below.

That is, the corner cube CC reflects the incident light in the same direction as the incident direction. Now, consider light L1 that is incident on the Kohno cube CC at an incident angle θ1. This incident light L1 is transmitted to the light reflection side 18 to 3a inside the corner cube 1.
It is reflected multiple times (twice) at the corner cube CC and exits from a position symmetrical with respect to the optical axis O of the corner cube CC. At this time, the reflected light L1 is parallel to the incident light L1, and its reflection angle is equal to the incident angle of the incident light L1. Therefore, the reflected light L1 is
The incident light L1 is reflected in the same direction as the incident direction. This relationship holds true regardless of the angle of incidence of the incident light. For example, the incident light L2 and the reflected light L2 are parallel to each other, and the incident angle of the incident light L2 and the reflection angle of the reflected light L2 are both equal to 02.

FIG. 3 is a diagram showing a state in which the inclination angle of a moving body (2) is measured using an embodiment of the present invention. Figure 4 is a moving object■
3 is a diagram of the beam scanner BS seen from above, showing the scanning state of the light beam. FIG.

FIG. 5 is a diagram showing the relationship between the mask MA formed on the corner cube CC and its reflected light.

First, before explaining the details of the embodiment of the present invention, the principle of the embodiment will be explained with reference to FIGS. 3 to 5.

As shown in FIG. 3, the corner cube CC is fixed in place. On the other hand, a beam scanner BS is provided at the front of the moving body V. This beam scanner BS generates a sharply directional light beam, such as a laser beam, and rotates and scans it toward the corner cube CC, as shown in FIG.

On the other hand, a mask MA is formed of, for example, paint or paper in a predetermined area of the light reflecting mirror surface of the corner cube CC. In the example shown in FIG.
A mask MA is formed in the scaly area). Note that the mask MA is formed so that the center and peripheral parts of the corner cube CC are exposed. Since the light incident on the portion where the mask MA is formed does not hit the light reflecting mirror surface 3a, it is not reflected in the same direction as the incident direction.

By the way, the areas MA' and M A '' indicated by dotted lines in FIG. 5 are areas shaded by the mask MA. That is, these areas 1i1iMA' and M A ''
The light incident on the surface is once reflected by the light reflection surface, but 2
Since the light hits the mask MA during the second or third reflection, it is not reflected in the same direction as the incident light direction.

The corner cube CC as described above is fixed at a predetermined position as shown in FIG. 3, but at that time, one side of the mask MA is aligned with a predetermined reference line adjusted to match.

Now, let us consider the case where the light beam from the beam scanner BS passes through the optical axis center 00 of the corner cube CC and scans over the corner cube as shown in A-B or C-+D shown in FIG. When the light beam is scanned from A to B, the scanning line on the corner cube CC is the reference line X-x
(in FIG. 5), the scanning line is in the mask MA, the area MA' and the MA
Therefore, at this time, the reflected light from the corner cube CC includes one wide pulse, as shown in FIG. 5.On the other hand,
When the light beam from the beam scanner is scanned from C to D, that is, when the scanning line on the corner cube CC is downward to the right with respect to the reference line XX (in Fig. 5), the scanning line is in the area MA' and mask MA.

Therefore, the reflected light from the corner cube CC at this time includes three pulses as shown in FIG. 5.

The moving object (■) receives the reflected light from the corner cube CC as described above, and by counting the number of pulses, determines whether the scanning line is upward to the right or downward to the right with respect to the reference line x-X. Determine whether

Then, based on the determination result, the scanning line is set to the reference line
Rotate the scanning plane of the light beam so that it coincides with X.

If the rotation angle of the scanning plane of the light beam at that time is detected,
It is possible to measure the inclination angle of the moving body (2) with respect to the reference aX-X. In addition, in FIG. 3, since the light beam is rotated and scanned toward the front of the moving object (2), it is possible to measure the horizontal inclination of the moving object (2) with respect to the reference line X-x. If the light beam is rotated and scanned toward the right or left side of the moving object V, the reference line X-X
It is possible to measure the inclination of the moving body V in the front-back direction with respect to the front-back direction.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 68 to 11.

FIGS. 6A and 6B are external views showing the beam scanner BS installed on the moving object (2), and in particular, FIG. 6A shows its side view, and FIG. 6B shows its top view. In the figure, the beam scanner BS includes a cylinder 4 housing a laser light source and a light receiving element, and a rotary encoder EC1 and a motor M1 connected to the cylinder 4. By rotating the cylinder 4, the motor M1 rotates and scans the laser beam B. 〇-Tari encoder ECI detects the rotation angle of motor M1 and therefore the rotation angle of laser beam LB. Rotary encoder EC1, cylinder 4
The motor M1 is held by a holding member 5. A rotary encoder E is provided at the center of the side surface of this holding member 5.
C2 and motor M2 are connected. The motor M2 rotates the holding member 5, thereby rotating the optical scanning surface formed by the laser beam LB. Rotary encoder E
C2 detects the rotation angle of the motor M2 and therefore the rotation angle of the optical scanning surface. On the outer peripheral side of motor M2,
Motor M3 and rotary encoder EC3 are connected. By rotating the motor M2, the motor M3 rotates the optical scanning area formed by the laser beam LB in the vertical direction in FIG. 6A. The rotary encoder EC3 detects the vertical rotation angle of the motor M3 and therefore the optical scanning surface. Motor M3 and rotary encoder E
C3 is held by the holding member 6. This holding member 6
is fixed to the moving body V.

FIG. 7 is a longitudinal sectional view of the cylinder 4 shown in FIG. 6A. In the figure, a laser light source 5 such as a semiconductor laser is provided on the inner peripheral wall of a cylinder 1.

The laser beam LB emitted from this laser light source 5 is
The light is emitted to the outside from a hole 6 formed in the side surface of the cylinder 4.

Further, inside the cylinder 4, a half mirror 7 is arranged at an angle of approximately 45 degrees on the optical path of the laser beam LB. This half mirror 7 allows the laser beam LB from the laser light source 5 to pass therethrough, and also reflects the light reflected by the corner cube CC toward the bottom surface 41 of the cylinder 4 .

A light receiving element BD for receiving light reflected by the half mirror 7 is arranged on the bottom surface 41 of the cylinder 4. As shown in FIG. 8, this light-receiving element BD consists of semicircular light-receiving elements BD1 and BO2 and a small circular light-receiving element BDO arranged in the center.

FIG. 9 is a schematic block diagram of one embodiment of the present invention.

In the figure, the CPU 10 includes a ROM 11 and a RAM.
12 are connected. The ROM 11 stores an operating program as shown in FIG. 10, for example, and the CPU 10 operates according to this operating program. An interface 13 is further connected to the cpuio. This interface 13 is given light receiving outputs from the light receiving elements 800.8DI and BO2. Further, the outputs of these light receiving elements BDO, BD1 and BO2 are given to the interface 13 via the OR gate 14. Furthermore, the interface 13 includes drive circuits 15 and 166.
and 17 are connected. Each of the drive circuits 15 to 17 drives the motors M1 to M3 based on control signals given from the CPU 10 via the interface 13. Furthermore, the interface 13 includes encoders EC1 to
Angle output from EC3 is provided.

FIG. 10 is a flowchart for explaining the operation of the cpuio shown in FIG.

The operation of the -* embodiment of the present invention will be described below.

First, step 1 (abbreviated as S in the illustration) shown in FIG.
At this point, the drive circuit 15 is activated, and rotational scanning of the laser beam LB by the motor M1 is started. continue,
In step 2, the pattern of the light receiving output of the light receiving element BD is read. In other words, the output of the OR gate is sampled and stored in the RAM 12, and is sent to the CPU 1.
0 reads the pattern of the light reception output stored at that time from the RAM 12 each time one scan of the laser beam LB by the motor M1 is completed. Subsequently, the process proceeds to step 3, where it is determined whether the scanning line on the corner cube CC passes through the optical axis center OO of the corner cube CC. This determination is made based on whether or not the light receiving element BDO has derived a light receiving output during one scan of the laser beam 1-B. In other words, the optical axis center of the corner cube CC is 00 (
The light incident in the vicinity (see FIG. 5) returns to the beam scanner BS following the same optical path as the incident light.

The laser beam that has returned in this way is sent to the half mirror 7.
The light is reflected by the light and hits the light receiving element BD located at the center of the light receiving element BD. Therefore, if the light receiving output is derived from the light receiving element BDo during one scan of the laser beam LB, the scanning line on the corner cube CC will be at the optical axis center OO.
It means that you are passing above.

If it is determined in step 3 above that the scanning line on the corner cube CC does not pass over the optical axis center OO, the process proceeds to step 4. In this step 4, it is determined whether the scanning line is shifted above the reference line X-x (in FIG. 5). If the scan line is the reference mx-x
If it is determined that the position has shifted upward, the process proceeds to step 5, and the motor M3 is rotated in the Tokita direction (direction of arrow R) in FIG. 6A. With this, Corner Cue 1C
The scanning line on C gradually goes down. On the other hand, if it is determined in step 4 that the scanning line is shifted below the reference line XX, the process proceeds to step 6. In this step 6,
Contrary to step 5, the motor M3 is rotated in the counterclockwise direction (in the direction of the arrow) at a5 in FIG. 6A. This causes the scan line to gradually rise. Steps 5 and 6 above
After that, the operations from step 2 onwards are repeated again.

Here, whether or not the scanning line is shifted upward is determined by which of the light receiving elements BDI and BO2 derives the light reception output longer in one scan, and the reason for this will be explained below. . As explained in FIG. 1, the light incident on the corner cube CC does not exit from the same part, but from a point symmetrical position with respect to the optical axis O. Therefore, for example, in the corner cube CC of FIG. 5, the light incident on the light reflecting mirror surface above the reference line
The light is reflected by the light reflecting mirror surface below X and is emitted. Conversely, the light incident on the light reflecting mirror surface below the reference line
The light is reflected by the light reflecting mirror surface above it and exits. On the other hand, the light receiving element BD1 is arranged to receive the light emitted from the reflective mirror surface below the reference line XX. Further, the light receiving element BD2 is arranged so as to receive the light emitted from the reflecting mirror surface above the reference aX-X. Now, if we consider the case where the scanning line on the corner cube CC is shifted upward with respect to the optical axis center OO, in this case, the upper scanning line is higher than the lower scanning line with reference line is also longer. Therefore, the reflected light emitted from the corner cube CC takes longer time to exit from the lower light reflecting mirror surface with respect to the reference line XX as a boundary than it takes to exit from the upper light reflecting mirror surface. Accordingly, in the light receiving element BD, the light receiving time of the light receiving element BD1 becomes longer than the light receiving time of the light receiving element BD2. Therefore, when the time for deriving the light receiving output from the light receiving element BD1 is longer than the deriving time for the light receiving output from the light receiving element BD2, it can be determined that the scanning line is shifted upward with respect to the optical axis center 00. Contrary to the above, the light receiving element B
If the time for deriving the light receiving output from D2 is longer than the time for deriving the light receiving output from light receiving element BD1, it can be determined that the scanning line is shifted downward with respect to the optical axis center 00.

When the scanning line passes over the optical axis center 00 of the corner cube CC by repeating the operations in steps 2 to 6, this is determined in step 3, and the process proceeds to step 7. In step 7, the one-corner output of the rotary encoder EC3 is stored in the RAM 12. Note that the angle output of the rotary encoder EC3 at this time represents the elevation angle of the corner cube CC with respect to the moving body V.

Next, the process proceeds to step 8, where the angular output of the encoder EC2 is stored and the pattern of the light receiving output of the light receiving element BD is read again. Then, the process proceeds to step 9, where the pattern of the light reception output read this time is compared with the light reception output pattern read at the end of the previous scan and the time before the previous scan. Specifically, the number of pulses included in the received light outputs is compared. If the number of pulses is the same, it is determined that the pattern is the same, and if the number of pulses is different, it is determined that the pattern is different. As shown in FIG. 5, when the scanning line is upward to the right, the received light output includes one pulse, and conversely, when the scanning line is downward to the right, the received light output includes three pulses. Subsequently, in step 10, based on the comparison result in step 9, the scanning line on the corner cube CC is aligned with the reference line x-X.
It is determined whether or not they match. If the received light output pattern read this time is different from the received light output pattern read last time, and the received light output pattern read this time is the same as the received light output pattern read the day before last, then the scanning line is the reference line. It is determined that it matches XX. That is, in this embodiment, it is assumed that the scanning line coincides with the sharp reference line XX, which alternately slants upward to the right and downward to the right in the vicinity of the reference line xx.

In step 10 described above, if it is determined that the scanning line coincides with the reference line xx (6), the process proceeds to step 11.

In this step 11, it is determined whether the scanning line on the corner cube CC is in a state of rising upward to the right (in FIG. 5) with respect to the reference line XX. This judgment is made in step 8 above.
This is done based on the pattern of the received light output that is read.

That is, if the received light output includes one pulse, it is determined that the scanning line is upward-sloping to the right, and if the received light output includes a pulse of 3111i1, it is determined that the scanning line is downward-sloping to the right.

If it is determined that the scanning line is upward-sloping, step 12
Then, the motor M2 is rotated in a direction in which the scanning line descends to the right. On the other hand, if it is determined that the scanning line is downward to the right, the process proceeds to step 13, where the motor M2 is rotated in a direction in which the scanning line is upward to the right. After steps 12 and 13, the operations from step 8 onwards are repeated again. When the operations of steps 8 to 13 are repeated and it is determined that the scanning line coincides with the reference line X-x, the process proceeds to step 14. In this step 14, the average angle between the angle output of the rotary encoder EC2 read this time and the angle output of the rotary encoder EC2 read last time is calculated. Then, the average angle is stored in the RAM 12 as the inclination angle of the moving body V with respect to the reference mx-x. After that, the operation returns to step 2 again.

FIG. 11 is a diagram showing another example of the mask formed on the corner cube CC. In the figure, corner cube CC
A plurality of rows of masks MA1 to MA4 are formed on the reflective mirror surface 3a. Note that the mask formed on the corner cube CC is not limited to those shown in FIGS. 5 and 11, and various other masks may be used. That is, the mask may be formed so that the pattern of reflected light changes depending on whether the scanning line is upward to the right or downward to the right with respect to the reference line.

In the above-mentioned embodiment, the inclination angle of the moving object (1) with respect to the reference line x-x is measured (1=), but of course the inclination angle of a fixed object can also be measured. In addition, mobile
The vehicle is not limited to one that travels on the ground, but may also be one that flies in the air like an airplane.

Effects of the Invention As described above, according to the present invention, the inclination angle of an object is measured using the special optical property of the light reflecting means that reflects light in the same direction as the incident light. , the inclination angle can be measured very accurately, and the device is simple and inexpensive.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of the corner cube. FIG. 2 is a three-dimensional perspective view of a mirror housed inside the corner cube. FIG. 3 is a diagram showing a state in which the inclination angle of a moving body (2) is measured using an embodiment of the present invention. Fourth
The figure is a view of the beam scanner BS from above the moving body V, and shows the scanning state of the light beam. FIG. 5 is a diagram showing the relationship between the mask MA formed on the corner cube CC and its reflected light. 6A and 6B are external views showing a beam scanner BS used in an embodiment of the present invention, in particular, FIG. 6A shows its side view, and FIG. 6B shows its top view. FIG. 7 is a longitudinal sectional view of the cylinder 4 shown in FIG. 6A. FIG. 8 is a plan view of the light receiving element BD shown in FIG. 7. FIG. 9 is a schematic block diagram of an embodiment of the present invention. Figure 10 shows the CPU shown in Figure 9.
2 is a flowchart for showing the operation of 0. 11th
The figure shows another example of the mask formed on the corner cube CC. In the figure, CC is a corner cube, ■ is a moving object, and BS
is a beam scanner, 18 to 3a are light reflecting mirror surfaces, MA is a mask, MA' and MA'' are shadows created by the mask MA, M1 to M3 are motors, EC1 to EC3 are encoders, 5 is a laser light source, and BD is a light receiver element, 10 is CPU
, 11 is ROM. 12 indicates a RAM. Patent applicant Toshihiro Tsumura (and 2 others) Figure 5 E = 43 - Procedural amendment (formality) Director General of the Japan Patent Office 1, Indication of the matter Patent application No. 10813f of 1988 2, Mitsushige's name Middle oblique breast 1 measurement Gino, boom 3, person who overturns correction ``Interaction with F Special W ) 4. Agent address: 2-3-9 Tenjinbashi, Kita-ku, Osaka
Bill September 27, 1981 6, Full text of old surveyed fields subject to amendment 7, Contents of amendment attached to J3. However, there may be no amendments to the content. Above procedures amended June 18, 1982 2 Name of the invention Inclination angle measurement system 3 Person making the amendment IPL person in charge of the case Patent applicant address 15, Sumiyoshi-ku, Osaka City! Sunzi 3-7-21 Tsumura Toshihiro Name: Toshihiro Tsumura ((1 person) 4. Agent address: 2-3-9J Tenjin Enoki, Kita-ku, Osaka City Yachiyo Daiichi Kale voluntary amendment 6. Drawings subject to amendment Figure 10 7, Contents of Amendment Figure 10 of the drawing is corrected as shown in Figure 10 attached.

Claims (2)

[Claims] (1) A system that measures the angle made by an object with respect to a predetermined reference line, and has a plurality of mirror surfaces that are combined three-dimensionally to reflect incident light in the same direction. a reflecting means, a mask formed in a predetermined area of the light reflecting mirror surface, a rotary scanning means provided on the object and rotating and scanning a sharply directional light beam toward the light reflecting means; A light receiving means provided in association with the moving scanning means and for receiving the reflected light from the light reflecting means; a light receiving means provided in association with the rotary scanning means for displacing a light scanning surface formed by the light beam; a displacement means for driving the displacement means based on the output of the light receiving means so that the optical scanning surface coincides with the reference line;
and means for detecting the angle by detecting the amount of displacement of the optical scanning surface by the displacement means. (2) The displacement means includes: a first displacement means that displaces the optical scanning surface in a direction perpendicular to the optical scanning surface; and a second displacement means that rotates the optical scanning surface, and the driving means The first displacement means is driven so that the optical scanning surface hits the optical axis center of the light reflecting means, and then the second displacement means is driven to rotate the optical scanning surface and the base is moved. 2. The inclination angle measurement system according to claim 1, wherein the angle detection means includes means for detecting a rotation angle of the optical scanning surface by the second displacement means so as to coincide with the rP- line.